Delete assigned resource must return HTTP status code 409 Conflict

[stiliyan-v]

Changes Made:

• Added the new exception class CompasAssignedLocationException for cases when a location with assigned resources is attempted to be deleted.
• Updated LocationsService.deleteLocation to throw CompasAssignedLocationException instead of the more generic CompasSclDataServiceException when deletion is not allowed.
• Introduced CompasAssignedLocationExceptionHandler to map CompasAssignedLocationException to a 409 Conflict HTTP response with a structured error body.

Testing Updates:

• Added a unit test for CompasAssignedLocationExceptionHandler to verify correct error response mapping.
• Updated service and resource tests to expect and use CompasAssignedLocationException instead of the previous exception.